a chemistry experiment calls for 30% sulfuric acid solution. if the supply room has only 50% and 20% sulfuric acid solution on hand,how much of each should be mixed to obtain 12 litres of 30% solution?

Answer 1

Think of the total amounts of solute in the various concentrations. If you mix them, you get

.5x + .2(12-x) = .3(12)
.3x = 1.2
x = 4